Stargate from Stargate SG-1.
A Dragon Gate is a fantastic analog to the Stargates from Stargate SG-1, Stargate: Atlantis, and Stargate: Universe. They are a device that allows for rapid travel between two very distant locations. In Phaeselis, they are a device used to help explain the Lemurians, the appearance of many different races (dragons, elves, dwarves, orcs, et. al) in the world, and helps add an element of Science Fiction to the Fantasy World to make it more robust. It's not meant to be seen in game.